A quick setting ceramic that can be mixed in much the same way as phosphate concrete was originally developed by Argonne National Laboratory for radioactive and hazardous waste stabilization. This product is commonly referred to as Ceramicrete and has two components, a powder component and an aqueous component that are mixed together prior to use. The final Ceramicrete product is a magnesium potassium phosphate set material. The applications for Ceramicrete have been extended further to production of structural materials and in the process phosphosilicate ceramic was developed. Recent developments in Ceramicrete technology have been disclosed in several issued patents, all of which have Arun S. Wagh, one of the inventors of the present invention, as either a sole inventor or a co-inventor, including U.S. Pat. No. 5,645,518 issued Jul. 8, 1997; U.S. Pat. No. 5,830,815, issued Nov. 3, 1998; U.S. Pat. No. 5,864,894, issued Dec. 8, 1998; U.S. Pat. No. 6,133,498, issued Oct. 17, 2000 issued Oct. 17, 2000; U.S. Pat. No. 6,153,809 issued Nov. 28, 2000; U.S. Pat. No. 6,204,214 B1, issued Mar. 20, 2001; U.S. Pat. No. 6,498,119 B2, issued Dec. 24, 2002; U.S. Pat. No. 6,518,212 B1, issued Feb. 11, 2003; and U.S. Pat. No. 6,569,263 B2, issued May 27, 2003, which are incorporated herein by reference.
One ceramic material that has had some success as a binding material for industrial applications and waste management is the Ceramicrete binder. Ceramicrete binders disclosed include compounds such as magnesium potassium phosphate (MgKPO4.6H2O). These Ceramicrete binders are considerably less porous than conventional materials, are not toxic or flammable, set at a controllable rate, and are a low cost alternative to polymer resins.
The final set Ceramicrete phosphosilicate material is substantially without porosity. The substantially porosity-free Ceramicrete is made possible when calcium silicate (CaSiO3) is added to create an amorphous silico-phosphate phase, which forms between the more crystalline MgKPO4.6H2O. The final Ceramicrete phosphosilicate products have a compressive strength comparable to or greater than the compression strength exhibited by portland cement.
However, only biocompatible components can make up the binding materials used in dentistry and orthopedics. For example, zinc phosphate materials have been used as dental materials because they are dense, hard and also biocompatible. Zinc phosphate cements, however, are not strong and not adhesive to metal. For these reasons and higher cost than portland cement, zinc phosphate cements are not practical for use in construction or waste encapsulation projects as well. Zinc phosphate cements also do not contain calcium phosphates or hydroxylapatite, which are desirable elements for bone tissue growth.
None of the previous binding materials provide a high strength, low porosity, rapid setting, easily colored, bioactive chemical composition needed for use in the bio-material industries of dentistry and orthopedics.
The high strength and extremely low porosity of Ceramicrete are two properties that are important to the field of dental materials and bone cements. The basic Ceramicrete composition is biocompatible. However, Ceramicrete as it is currently designed lacks a number of characteristics that would permit it to be used in dental and orthopedics applications. These characteristics include quick-setting at room and body temperatures, a range of low to high viscosity of the paste prior to setting, bioactive, radiopaque, and good bonding with tooth and bone materials. In addition, Ceramicrete is not designed to be fluorescent, fluoride-releasing, radiopaque, or to be a good color match with natural dentition.
In addition, dental materials and bone cements should generally have low exothermic heat, since they are used on the human body, and dimensional stability, as such materials should not expand or change shape to any noticeable degree. In addition, the dry powers used should be fine-grained for a smooth texture and quick dissolution and reaction. The creation of a phosphosilicate material mixture that has a final phosphosilicate set material with such characteristics would require significant modifications to the original Ceramicrete formulations.
Significant advances in dental materials and orthopedic cements have been achieved through the development of novel compositions and methods. However, given the expectations for continuous improvements in the dental and medical fields, there is a continuing need for further improvements to methods and materials for bonding materials for dentistry and to bond bone to other pieces of bone and other ceramic or metallic restorative materials. Furthermore, the concept of bioactivity where a material introduced into the body, stimulates the body to respond with the formation of bone to heal a defect, is of increasing importance. The present invention fulfils this need and further provides related advantages.